World Tobacco Day 2020: Here's how smoking affects fertility in both men and women

It is not a secret that smoking is detrimental to our health. Most people are aware that it increases the risk for heart, vascular and lung diseases, however, still, a major chunk does not realize that the toxin contained in cigarettes can also affect fertility in both men and women leading to erectile dysfunction and pregnancy complications as well. Recent data shows that smoking habits may be responsible for fertility struggles in as many as 13% of couples. Smoking habits affect males and females quite differently, however, both can lead to the reason for fertility complications and average smoking of six to seven cigarettes a day can affect their ability to conceive.

Since it harms the child prenatally, it is always advisable to quit smoking even before considering pregnancy. As per a survey, about 30% of women of childbearing age knew that smoking could heighten the risk of miscarriage and about 10% are aware that it could also hurt their fertility. For each cigarette smoked per day, any couple will take much longer to get pregnant. Going with the fact, a woman who smokes four cigarettes per day will on average take more time to get pregnant than a woman who smokes just two per day. 

Smoking can be associated with the following fertility problems amongst women:

1. The complication in the fallopian tubes, including fertility blockages with an increased risk of ectopic pregnancy.

2. It can cause damages to the eggs whilst they develop in the ovaries.

3.Increased risk of miscarriage with damage to the developing fetus. This can also lead to unfavorable changes in the uterine lining, which may impede healthy embryo implantation.

4. In addition, it can cause cervical changes; specifically an increased risk of developing cervical cancer.

It is important to understand that except for the decline in ovarian reserve, not all of the above-mentioned issues are directly caused by smoking, however, smoking definitely aggravates that. Furthermore, along with complications with fertility now, it can lead to lowered fertility in the future. Men can produce new sperm throughout their lives, whereas in the case of women, they are born with all the eggs they will ever have. 

Therefore, once those eggs are damaged, nothing can be done to undo that. Smoking may drastically decrease the total number of eggs a woman has in her ovaries and can age the ovaries prematurely. Toxins in cigarettes may also lead to DNA damage to ovarian follicles, where the eggs usually mature. This premature aging of the ovaries and lessening in eggs may lead to earlier menopause amongst women, as much as four years earlier than usual.

Smoking harms male fertility equally. As per a meta-analysis by European Urology on the effect on semen health, shows that smoking was associated with decreased sperm count, decreased sperm motility, sperm concentration along with sperm DNA and poor sperm morphology.

Most notably, the negative effect smoking had on sperm health was stronger in infertile men and moderate to heavy smokers, compared to light smokers. Smoking across males is also associated with decreased IVF success rates and possibly increased miscarriage rates. Indirect smoke can harm the female partner's fertility as well. Therefore, every time he smokes, it not only decreases his sperm health, but it also decreases her fertility.

The habit of smoking exposes men to high levels of cadmium and lead, metals that are associated with decreased fertility. Lead levels are significantly at an upper level in infertile smokers if compared to both fertile and infertile non-smokers. Heavy smokers with smoking habits of 20 or more cigarettes a day are likely to have higher levels of cadmium in their semen.

It is also directly correlated with an increased risk of erectile dysfunction, with a few recent studies showing a three-fold increase in risk for male smokers. Though erectile dysfunction is not the same as infertility. However, with difficulty in sexual performance, chances of conceiving would be critical. Therefore, quitting smoking is strongly connected to one’s sexual performance and hence, fertility.

By Dr. Apurva Satish Amarnath, Fertility Consultant, Nova IVF Fertility Bangalore